Estimation of mercury released into the environment from the uncontrolled dumping of broken medical thermometers in hospitals in Cameroon, Africa

The yearly mercury released into the environment from discarded broken thermometers was estimated through questionnaires submitted to medical personnel in two major cities, namely Yaounde and Bertoua, in Cameroon. Eighty-three medical personnel made up of 17 assistant nurses, 56 nurses + midwives and 10 physicians responded to have handled a total of 3216 units of thermometers made up of 85% Hg-added and 15% digital during consultations. Six hundred twenty-four units, all Hg-added and making about 19% of thermometers got broken during health consultations. This breakage led to the average annual disposal of 0.646 Kg of mercury. The mean rates of mercury release from broken thermometers were assessed to 0.056, 0.005 and 0, and 0.009, 0.002 and 0 Kg per year, respectively, for assistant nurses, nurses + midwives and physicians in bigger and smaller cities, respectively. Assistant nurses alone disposed of 73%, 27% by nurses + midwives, and none released by physicians for the total estimated of 222.52 Kg of mercury disposed of from broken thermometers by medical personnel in hospitals in Cameroon. Out of the total mercury estimated, 63.71% and 36.21% were disposed of by medical personnel in bigger and smaller cities, respectively. The circumstances of the accidental broken of these mercury-added thermometers will expose medical personnel, patients, and the public to this toxic chemical.

Assessment of heavy metals' pollutions and potential risks associated to the rocks of Pouma subdivision-Cameroon

The present study aimed to assess the ecological and health risks of the Pouma rock samples. Twenty-three (23) trace element concentrations were evaluated. The concentrations of these trace elements were compared with those of quartzite from other countries and with global reported values. When compared with the world values, the concentrations of trace metals were below the world average values except that of Barium. The ecological risk assessment was carried out using the geo-accumulation index, contamination factors and the potential ecological risk index. The geo-accumulation index and contamination factors showed that the quartzite of Pouma subdivision are not polluted and not contaminated by the investigated metal except for Barium and Mercury. The health risk assessment using the USEPA (United States Environmental Protection Agency) method showed that there is a possible non-carcinogenic risk from Al2O3 (for children and adults) and from Cr for Children. However, there is a tolerable and high carcinogenic risk due to Cr for adults and children, respectively. It was found independently for non-carcinogenic and carcinogenic risk that the exposure via the ingestion route is the most dangerous for adults and children.

Advanced monitoring and numerical modelling of the stability, safety and reliability indicators of the earthen dam of Songloulou (Cameroon)

For the determination of global stability after long term advanced monitoring, artificial intelligence have been used for the data analysis of water level and displacements of Songloulou earth dam at Cameroon. Measurements of safety and reliability indicators follow changes set by piezometric and pendulums measurements. The results obtained from the artificial intelligence on the base of many years recording data have confirmed the relevance and robustness of this model. The ANFIS model combining the concept of neural network and fuzzy logic was used to simulate the behaviour of piezometers and pendulums in the dam. This model has provided satisfactory results, given in the large amount of data to be processed. The water level evolution is modelled using the ANFIS function integrated in the MATLAB software and the result is compared to that obtained by the HST method. Afterwards, the state of stress on the structure and stability of the slope at shear have been assessed based on the hydro mechanical behaviour using the GEOSTUDIO Finite Element computation software. The input parameters are: the head of water recorded in the piezometers and geotechnical parameters of the dam. The modelling results in terms of displacement are accurately consistent with the displacement measurements. The horizontal displacement of pendulums obtained by GEOSTUDIO is 80 mm and those measured directly of the pendulums have 70 mm of average value. The safety factor for slope stability according to 530 m water level is 1.5.

Impact of filtering face pieces (FFP3) respiratory protective mask usage on the respiratory functions of informal sector carpenters in Douala: a five-month before-after study

Introduction

informal sector carpenters in Douala, Cameroon, face potential risks to their respiratory health due to daily exposure to fine particles and wood dust. The study aims to demonstrate the importance of preventing respiratory problems in this population through regular use of filtering face pieces (FFP3) respiratory masks.

Methods

the before-after study involved 37 carpenters who wore FFP3 masks during their professional activities for five months. Spirometry measurements were taken before and after the intervention to assess changes in respiratory function.

Results

significant improvements were observed in forced vital capacity (FVC) 89.6 % to 95.0 % (p<0.000), forced expiratory volume in one second (FEV1) 88.1 % to 95.0 % (p<0.000), Tiffeneau index 82.4 to 84.9 (p<0.000), and peak expiratory flow (PEF) 6.7 l/s to 7.9 l/s (p<0.000) after mask usage, indicating enhanced lung function.

Conclusion

the regular use of FFP3 masks had a positive impact on the respiratory health of informal sector carpenters in Douala, enhancing lung function and reducing airway obstruction. The study highlights the importance of preventive measures to safeguard the respiratory well-being of workers exposed to occupational hazards. Spell out Greek characters (i.e: alpha, beta).

Mycobacterium tuberculosis complex drug-resistance, phylogenetics, and evolution in Nigeria: Comparison with Ghana and Cameroon

In this article, we provide an in-depth analysis on the drug-resistance phenotypic characteristics of a cohort of 325 tuberculosis and characterize by Whole Genome Sequencing 24 isolates from Nigeria belonging to L4, L5 and L6. Our results suggest an alarming rate of drug-resistance of the L4.6.2.2 Mycobacterium tuberculosis complex (MTBC) lineage and a high diversity of L5. We compiled these new Sequence Read Archives (SRAs) to previously published ones from available Bioprojects run in Nigeria. We performed RAxML phylogenetic reconstructions of larger samples that include public NCBI SRAs from some neighboring countries (Cameroon, Ghana). To confront phylogenetic reconstruction to metadata, we used a new proprietary database named TB-Annotator. We show that L5 genomes in Northern Nigeria belong to new clades as the ones described until now and allow an update of the taxonomy of L5. In addition, we describe the L4.6.2.2 lineage in Nigeria, Cameroon and Ghana. We provide computations on the likely divergence time of L4.6.2.2 and suggest a new hypothesis concerning its origin. Finally we provide a short overview on M. bovis diversity in Nigeria. This study constitutes a baseline knowledge on the global genomic diversity, phylogeography and phylodynamics of MTBC in Nigeria, as well as on the natural history of this largely ignored but densely populated country of Africa. These results highlight the need of sequencing additional MTBC genomes in Nigeria and more generally in West-Africa, both for public health and for academic reasons. The likelihood of replacement of L5-L6 by L4.6.2.2 isolates, leave potentially little time to gather historical knowledge informative on the ancient history of tuberculosis in West-Africa.

Identification of some microbial flora contained in slaughterhouse effluent and likely to be effective in its treatment by biological process

The specific contributions of the different bacterial flora during the biological treatment of slaughterhouse effluents remain unclear. The objective of this study is to identify the different microbial flora which mainly contribute to the efficiency of the biodegradation of the organic, nitrogenous and phosphate loads contained in the slaughterhouse effluent during its biological treatment. To achieve this, the effluent to be treated was sampled from three slaughterhouses in the city of Ngaoundéré (Cameroon). The various effluents underwent a physicochemical and microbiological characterization. The effluent was subjected to biological treatment. The biodegradation process (biological treatment) took place in two reactors, each operating in batch. One of the two reactors was supplied with oxygen (aeration). The effluent being treated underwent a physicochemical and microbiological characterization for 30 days. The results obtained show organic matter and ammonium contents >1,000 mgO2/L in each of the three effluents. Bacillus cereus (69 × 108 CFU/mL), Pseudomonas aeruginosa (201 × 107 colony forming unit (CFU)/mL) and Yeasts (101 × 106 CFU/mL) globally constitute the majority of microbial groups among the seven microorganisms identified in the effluents of the three slaughterhouses. There is no real oxygenation effect of the medium on the growth of the three microbial flora during the treatment.

[Antithrombotiques oraux et pronostic après un an des patients atteints de fibrillation auriculaire dans un milieu à ressources limitées]

BACKGROUND

Atrial fibrillation is associated with increased risk of morbidity and mortality. There's limited data on the outcomes of atrial fibrillation patients in Africa. We aimed at evaluating the clinical outcomes and their associated factors in patients with atrial fibrillation on antithrombotic therapy in Douala.

METHODS

The Douala atrial fibrillation registry is a prospective, observational cohort study of patients with atrial fibrillation followed by cardiovascular specialists in 3 specialized care centres. From January to April 2018, all patients with electrocardiographic diagnosis of atrial fibrillation, aged 21 years or older, were included in the registry provided their consent. The composite endpoint of heart failure, stroke, major bleeding, hospitalisation and mortality as well as their individual occurrence were assessed at 12 months.

RESULTS

Of 113 participants that were included, 6(5.3%) were lost to follow-up. The mean age was 70 ± 12 years, with a female predominance (68%). After a mean follow-up time of 12.2 ± 0.7 months, 51 patients (47.7%) had at least one outcome. Hospitalisation, all-cause mortality, heart failure, stroke and major bleeding rates were 33.3%, 16.8%, 15.2%, 4.8% and 2.9% respectively. There was no significant difference in the composite outcome and mortality according to the antithrombotic treatment. Previous heart failure [aHR = 3.07, 95% CI (1.48-6.36) p = 0.003], new onset atrial fibrillation [aHR= 4.00, 95% CI (0.96-8.19) p < 0.001] and paroxystic atrial fibrillation [aHR= 3.74, 95% CI (1.33-10.53) p = 0.013] were significant predictors of outcome.

CONCLUSION

Half of patients with atrial fibrillation in this registry developed an outcome after one year of follow-up, with heart failure, new onset and paroxystic atrial fibrillation being the main predicting factors. Diagnosing and managing atrial fibrillation in patients with heart disease should therefore be considered as a key priority.

Performance of systolic pressure index for lower limb peripheral arterial disease in a group of elderly in sub-Saharan Africa

BACKGROUND

The automatic measurement of the ankle-brachial index (ABI) constitutes a reliable, simple, safe, rapid, and inexpensive alternative diagnostic screening test compared with the Doppler method for peripheral arterial disease (PAD). We aimed to compare the diagnostic performance of automatic ABI measurement tests to Doppler ultrasound for PAD in a group of patients aged 65 years and above, in Sub-Saharan Africa.

METHODS

This was an experimental comparative study of the performance of Doppler ultrasound to the automated ABI test in the diagnosis of PAD in patients aged ≥ 65 years followed-up at the Yaoundé Central Hospital, Cameroon between January to June 2018. An ABI threshold < 0.90 is defined as a PAD. We compare the sensitivity, and specificity of the high ankle-brachial index (ABI-HIGH), low ankle-brachial index (ABI-LOW), and the mean ankle-brachial index (ABI-MEAN) for both tests.

RESULTS

We included 137 subjects with an average age of 71.7 ± 6.8 years. In the ABI-HIGH mode, the automatic device had a sensitivity of 55% and a specificity of 98.35% with a difference between the two techniques of d = 0.024 (p = 0.016). In the ABI-MEAN mode, it had a sensitivity of 40.63% and a specificity of 99.15%; d = 0.071 (p < 0.0001). In the ABI-LOW mode, it had a sensitivity of 30.95% and a specificity of 99.11%; d = 0.119 (p < 0.0001).

CONCLUSION

The Automatic measurement of systolic pressure index has a better diagnostic performance in the detection of Peripheral Arterial Disease compared to the reference method by continuous Doppler in sub-Saharan African subjects aged ≥ 65 years.

Hospital Detention for the Inability to Pay: A Qualitative Study of Patient Experiences in Cameroon

INTRODUCTION

Equitable access to quality surgical care and low-cost healthcare services for all segments of the population remains a big problem in many African health systems. In Cameroon, it is very common to find medically discharged patients who have received surgical treatment and are unable to pay the resulting bills. These patients can be held in detention in hospitals until payments are complete. Even the corpses of patients who die with unpaid medical bills can be withheld until their family members pay off the debt. While this practice has been ongoing for many y, there remains very little scholarship on the issue reported in the literature. The main objective of this study was to uncover the lived experiences of discharged patients residing in hospital detention for being unable to pay their medical bills.

METHODS

In-depth interviews, focus group discussions, and observations were conducted with purposefully selected patients living in detention in 2 rural private hospitals in the Fundong Health District in Cameroon. A thematic framework technique was used to analyze the transcribed data. The study was ethically approved by the Cameroon Bioethics Initiative, and informed consent was obtained from all participants.

RESULTS

Living in hospital detention after receiving treatment constitutes an economic, social, and psychological burden for patients. Economically, it exacerbated poverty for the patients unable to purchase food, medications, and clothing due to lack of jobs and financial support. Socially, many of these individuals suffered from isolation, loneliness, shame, stigma, risk of contracting other diseases, and precarious sleeping conditions. The psychological burden was comprised of stress, depression, trauma, nightmares, and suicidal thoughts.

CONCLUSIONS

The experiences of discharged patients in hospital detention suggest that they live in very deplorable conditions. There is a need for a functional healthcare protection mechanism, such as universal health coverage, to reduce the cost of healthcare services and surgical operations. Alternative payment mechanisms should also be considered.

Pubertal patterns in children with sickle cell anemia: A case-control study in Cameroon

BACKGROUND

Puberty may be impaired in children with sickle cell anemia (SCA). Therefore, we aimed to explore the clinical and hormonal features of puberty in Cameroonian children.

METHODS

In a case-control study, we included 64 children aged 8-18 years with SCA matched to healthy controls. We assessed height, weight, body mass index, body composition, and Tanner stages. Hormonal measurements included anti-mullerian hormone, follicle-stimulating hormone, luteinizing hormone, and sex hormones (estrogens/testosterone). We used the Mann-Whitney Wilcoxon test to compare the median values between cases and controls. We looked for associations between the severity criteria of SCA and delayed puberty through multivariate analysis.

RESULTS

Delayed puberty was reported in 27.3% of girls and 10% of boys with SCA. The median age of menarche was delayed by 2 years compared to controls. SCA patients had a low lean body mass compared to controls (p = 0.03). Anti-mullerian hormone levels were significantly higher in boys with SCA than those of controls (45.9 ng/mL vs. 17.65 ng/mL; p = 0.018). A history of severe infection, acute chest syndrome, and low hemoglobin level was associated with delayed sexual maturation in children with SCA.

CONCLUSION

Our study revealed delayed puberty in children with SCA. Moreover, puberty is affected by the severity of the disease. This highlights the importance of regular monitoring of puberty during the follow-up of these children.

A retrospective cohort study on the cost-effectiveness analysis of kidney transplantation compared to dialysis in Cameroon: evidence for policy

Introduction

chronic kidney disease affects one in ten adults in Cameroon. Haemodialysis was the only renal replacement therapy (for adults) in Cameroon and its sub-region until November 10, 2021. Thereafter through May 2022, the Yaoundé General Hospital successfully completed four living-donor kidney transplants. This paper examines policy implications.

Methods

medical records of cohorts of kidney failure patients who started haemodialysis at Yaoundé General Hospital in 2012 (n=106) and 2017 (n=118) were abstracted retrospectively through 2021 and their survival analyzed with Microsoft Excel and Kaplan-Meier curves. Using hospital data, the literature, and price indexes, the annual medical cost per patient of dialysis and living-donor kidney transplantation in 2022 prices was derived.

Results

the 9.5-year survival rate for the 2012 cohort was 11% and the 5-year rate for the 2017 cohort was 18%. Annual haemodialysis cost per patient averaged $17,681 (26.5% from households and 73.5% from government). Initial transplantation costs averaged $10,530 per patient, all borne by the government. Under the brand-drug option, first-year transplantation follow-up costs $19,070 (4% for laboratory and 96% for drugs).

Conclusion

annually, haemodialysis in Cameroon costs per patient 12 times the country's average income ($1,537), driven especially by the costs of equipment purchase, maintenance, and consumables. Cameroon's initial cost of transplantation is lower than in other African countries. Generic drugs could lower annual follow-up costs by 89%. If Cameroon could achieve long-term survival with generic drugs after kidney transplantation, that modality would become a reasonable option for selected kidney failure patients (e.g. younger and without other comorbidities).

Soluble biomarkers of HIV-1-related systemic immune activation are associated with high plasma levels of growth factors implicated in the pathogenesis of Kaposi sarcoma in adults

Background

Human Herpesvirus-8 (HHV-8) is the etiologic agent of Kaposi's sarcoma (KS), a multicentric angio-proliferative cancer commonly associated with Human Immunodeficiency Virus (HIV) infection. KS pathogenesis is a multifactorial condition hinged on immune dysfunction yet the mechanisms underlying the risk of developing KS in HHV-8 seropositive adults remains unclear. Here we explored whether soluble markers of HIV-1-related systemic immune activation (SIA) and angiogenesis (VEGF and FGF acidic) are involved in the pathogenesis of KS in adults with HHV8.

Methodology

Blood samples from 99 HIV-1 infected and 60 HIV-1 uninfected adults were collected in Yaoundé, Cameroon. CD3+/CD4+ T cell counts and HIV-1 plasma viral load were determined using the Pima Analyzer and the RT-PCR technique, respectively. Plasma levels of SIA biomarkers (sCD163, sCD25/IL-2Rα, and sCD40/TNFRSF5) and biomarkers of progression to KS (VEGF and FGF acidic) were measured using the Luminex assay. Seropositivity (IgG) for HHV-8 was determined using the ELISA method.

Results

Overall, 20.2% (20/99) of HIV-1 infected and 20% (12/60) of HIV-1 uninfected participants were seropositive for HHV8. Levels of sCD163, sCD25/IL-2Rα, sCD40/TNFRSF5, and FGF acidic were higher in the HIV-1 and HHV8 co-infection groups compared to the HIV-1 and HHV8 uninfected groups (all P <0.05). In addition, Higher plasma levels of VEGF correlated with sCD163 (rs = 0.58, P =0.0067) and sCD40/TNFRSF5 (rs = 0.59, P = 0.0064), while FGF acidic levels correlated with sCD40/TNFRSF5 (rs = 0.51, P = 0.022) in co-infected. In HIV-1 mono-infected donors, VEGF and FGF acidic levels correlated with sCD163 (rs =0.25, P = 0.03 and rs = 0.30, P = 0.006 respectively), sCD25/IL-2Rα (rs = 0.5, P <0.0001 and rs = 0.55, P <0.0001 respectively) and sCD40/TNFRSF5 (rs = 0.7, P <0.0001 and rs = 0.59, P <0.0001 respectively) and even in patients that were virally suppressed sCD25/IL-2Rα (rs = 0.39, P = 0.012 and rs = 0.53, P = 0.0004 respectively) and sCD40/TNFRSF5 (rs = 0.81, P <0.0001 and rs = 0.44, P = 0.0045 respectively).

Conclusion

Our findings suggest that although the development of KS in PLWH is multifactorial, HIV-associated SIA might be among the key drivers in coinfections with HHV8 and is independent of the patients' viremic status.

Molecular detection of Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts in wild population of tsetse flies collected in Cameroon, Chad and Nigeria

BACKGROUND

Tsetse flies are cyclical vectors of African trypanosomiasis (AT). The flies have established symbiotic associations with different bacteria that influence certain aspects of their physiology. Vector competence of tsetse flies for different trypanosome species is highly variable and is suggested to be affected by bacterial endosymbionts amongst other factors. Symbiotic interactions may provide an avenue for AT control. The current study provided prevalence of three tsetse symbionts in Glossina species from Cameroon, Chad and Nigeria.

RESULTS

Tsetse flies were collected and dissected from five different locations. DNA was extracted and polymerase chain reaction used to detect presence of Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts, using species specific primers. A total of 848 tsetse samples were analysed: Glossina morsitans submorsitans (47.52%), Glossina palpalis palpalis (37.26%), Glossina fuscipes fuscipes (9.08%) and Glossina tachinoides (6.13%). Only 95 (11.20%) were infected with at least one of the three symbionts. Among infected flies, six (6.31%) had Wolbachia and Spiroplasma mixed infection. The overall symbiont prevalence was 0.88, 3.66 and 11.00% respectively, for Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts. Prevalence varied between countries and tsetse fly species. Neither Spiroplasma species nor S. glossinidius were detected in samples from Cameroon and Nigeria respectively.

CONCLUSION

The present study revealed, for the first time, presence of Spiroplasma species infections in tsetse fly populations in Chad and Nigeria. These findings provide useful information on repertoire of bacterial flora of tsetse flies and incite more investigations to understand their implication in the vector competence of tsetse flies.

Barriers and facilitators to ART adherence among ART non-adherence people living with HIV in Cameroon: A qualitative phenomenological study

BACKGROUND

Antiretroviral therapy (ART) needs to be taken for life with near perfect levels of adherence for it to be effective. Nonetheless, ART non-adherence is still observed in sub-Saharan African (SSA) countries such as Cameroon. The objective of this study was to assess the factors influencing non-adherence and or adherence among people living with HIV (PLWH) who have experienced non-adherence to ART in Cameroon.

METHODS

A descriptive qualitative study of PLWH who have experienced non-adherence with ART in Cameroon was conducted. Data were collected using in-depth interviews. Collected data were analyzed using the NVIVO 12 software.

RESULTS

In total, 43 participants participated in this study. The Southwest and Littoral regions each contributed 15 (34.88%) of participants, participants' mean age was 37.1 years (SD: 9.81) and majority 34 (82.93%) were females. ART adherence barriers include those related to patient (forgetfulness, business with other things, unwillingness to swallow drugs daily), medication (side effects), health service (arrogance of caregivers, occasional drug shortages at treatment centre, poor counseling of patient), stigma (fear of status disclosure), use of alternative treatment (traditional medicine, prayers and deliverance), resource limitation (limited food, limited finances), environmental/social (limited or no home support), and political instability (disruption of free circulation by ghost towns, roadblocks and gunshots in some regions). ART adherence facilitators include social support (family and peer support), aligning treatment with patient's daily routines (align ART with schedule of family members), use of reminders (phone alarm, sound of church bell), health sector/caregiver support (messages to patient, financial support, proper counseling), and patient's awareness of HIV status/ART knowledge (awareness of HIV positive status, Knowledge of ART benefits).

CONCLUSION

ART adherence barriers in Cameroon include those related to patient, medication, health service, stigma, use of alternative treatment, resource limitation, environmental/social, and political instability. ART adherence facilitators include social support, aligning treatment with patient's daily routines, use of reminders, health sector/caregiver support, and patient's awareness of HIV status/ART knowledge. Given these barriers and facilitators, continuous information provision and consistent support both from patients' families and caregivers are needed to improve adherence among patients. Further studies including many regions and larger samples using both in-depth and focused group discussions as well as quantitative approaches are required to uncover the burden related to ART non-adherence.

Plasma IL-33 levels and immune activation in HIV-TB coinfection: a cross-sectional study in Yaoundé, Cameroon

Introduction

HIV-1 and Mtb are characterized by immune activation and unbalances production of cytokines, but the expression of IL33 in HIV/TB coinfection remain understudied. This study aimed to evaluate the level of IL-33 in plasma of HIV and M. tuberculosis (HIV/TB) coinfected patients compared to patients with respective mono infections in Yaoundé.

Methods

a cross-sectional study was conducted among patients attending the pneumology service and HIV treatment center of the Yaoundé Jamot Hospital. Plasma samples of 157 HIV/TB coinfected patients (n =26, 50% males and 50% females, mean age 39), HIV-1 monoinfected patients (n = 41, 41% males and 59% females, mean age 35), TB monoinfected patients (n = 48, 56% males and 44% females, mean age 37) and healthy controls (n = 42, 29% males and 71% females, mean age 32) were examined by enzyme-linked immunoassay (ELISA) to detect the levels of IL-33 cytokine.

Results

plasma level of IL-33 were higher in HIV/TB coinfected (33.1±30.9 pg/ml) and TB monoinfected individuals (15.1±2.9 pg/ml) compared to healthy controls (14.0±3.4 pg/ml) and could not be detected in most of the HIV-1 monoinfected individuals (12.6±8.7 pg/ml). Interestingly, the increased plasma level of IL-33 in HIV/TB coinfected patients showed a statistically significant difference between healthy controls (33.1±30.9 pg/ml vs 14.0±3.4 pg/ml, P<0.0001) and HIV-1 monoinfected patients (33.1±30.9 pg/ml vs 12.6±8.7 pg/ml, P=0.0002). We further found that IL-33 was higher in patients with high viral load group (40.6±59.7 pg/ml vs 12.6±1.8 pg/ml), P= 0.47) whereas patients under highly active antiretroviral therapy (HAART) showed decreased level of IL-33 concentration as the number of years under ART increased. Our data showed a positive association between plasma IL-33 and viral load in the context of HIV/TB coinfection in our study population with a positive Pearson coefficient of r=0.21.

Conclusion

this study indicates that plasma level of IL-33 differs among HIV/TB coinfected patients and respective monoinfections patients. The increased level of plasma IL-33 reveals that IL-33 measurement in HIV-1 monoinfected patients may represent an early predictor of development of tuberculosis.

COVID-19 Vaccine Hesitancy in Cameroon: The Role of Medical Mistrust and Social Media Use

Most African countries report low COVID-19 vaccination rates (Msellati et al., 2022; WHO Africa; 2020). This study focuses on factors associated with vaccine hesitancy specifically in the country of Cameroon. Social media use and medical mistrust have been suggested as key variables that may increase vaccine hesitancy. Adopting the information-related perspective guided by the risk information seeking and processing model, the current research explored how social media use and medical mistrust are related to vaccine hesitancy among Cameroonians. Survey results from a sample of 1,000 Cameroonians fielded in early 2022 showed that social media use and medical mistrust were positively associated with belief in misinformation related to the COVID-19 vaccine. Belief in misinformation about the COVID-19 vaccine was negatively associated with perceived information insufficiency. A positive relationship between perceived information insufficiency and information seeking, as well as a negative relationship between information seeking and vaccine hesitancy were also found. Theoretical and practical implications are discussed.

Radiographic Evaluation of Impacted Third Mandibular Molar According to the Classification of Winter, Pell and Gregory in a Sample of Cameroonian Population

Background

The extraction of impacted third molars (M3) is a common surgical procedure in dentistry and oral surgery. Various complications, including inferior alveolar nerve (IAN) damage, may occur during and after extraction of this tooth. Radiographic examination should provide information about the M3 itself, but also about the surrounding bony structure and the relationship of the roots to the IAN and the adjacent second molar, which is often traumatized during this extraction. The aim of our study was to evaluate the depth and angulation of impacted mandibular third molars (M3) from panoramic radiographs, according to the classifications proposed by Winter and Pell & Gregory.

Methods

Radiographic signs present on the orthopantomogram showing M3 depth, and retromandibular available space according to the Pell & Gregory classification were evaluated. Evaluation of the M3 angulation relative to the M2 according to Winter's classification was also done. Student's t test was used to determine the association between side or sex and different variables.

Results

The depth of impaction of the M3 crown was level A accounting for 54.4% (n=260) of the PR while level B constituted 35.7% (n=171) of the images. Regarding the availability of retromandibular space, Class I constituted 36.8% (n=176). The Class II accounted for 55.9% (n=267) of PR.

Conclusion

Our study showed that 54.4% of M3 were located at the same level as the occlusal plane of the second molar, while in 56% of PR the space between the second molar and the ramus of the mandible is less than the mesiodistal diameter of the third molar. This research showed that 23.1% of M3 had a level of vertical angulation, a level that allows for less painful luxation of the impacted molars. These results seem to show a relatively high level of difficulty in mobilizing and extracting M3 from Cameroonian patients.

First Detection and Characterization of Hepatitis E Virus in Sewage Samples in Cameroon

Hepatitis E virus (HEV) represents an important public health concern in many developing countries, including Africa. Transmission of HEV to humans by contaminated drinking water is the most important mode of transmission in low- and middle-income countries. This study aimed to assess the presence of HEV in the environment in Cameroon through molecular analysis of sewage samples. Retrospectively, a total of 157 sewage samples collected between January 2018 and December 2019 were randomly selected and analyzed by molecular techniques to detect and characterize the HEV followed by sequencing and phylogenetic analysis. Three samples (1.9%) collected from North, Far North, and Adamawa regions were positive by real-time reverse transcription polymerization chain reaction. Among these, 2 samples were positive for HEV ribonucleic acid by nested reverse transcription polymerization chain reaction and only one yielded a good sequencing product. Phylogenetic analysis of this unique HEV strain showed that this HEV strain belonged to genotype 3, subtype 3a, and clustered with swine HEV strains from Cameroon, Argentina, and the USA. This study provides preliminary data on the circulation of HEV in wastewater in Cameroon. Further studies will be needed to assess the overall situation in Cameroon.

Can the use of larviciding with biological compounds contribute in increasing Anopheles gambiae s.l. susceptibility to pyrethroid in a population expressing high resistance intensity?

BACKGROUND

Larviciding using non-insecticide compounds is considered appropriate for controlling outdoor biting mosquitoes and for managing insecticide resistance. However, there is still not enough information on the influence of larviciding in managing pyrethroid resistance. In the present study, we checked whether the introduction of larviciding using the biolarvicide VectoMax G in the city of Yaoundé is contributing in restoring the susceptibility of An. coluzzii populations to pyrethroids.

METHODOLOGY

The susceptibility status of field An. coluzzii population was evaluated at different time points before and during larviciding treatments. In addition, An. coluzzii larvae collected in the city of Yaoundé, were split into four groups and exposed to different selection regimes for many generations as follow; (i): deltamethrin 0.05%_only, (ii): Vectomax_only, (iii): Vectomax+deltamethrin 0.05%, (iv): VectoMax+deltamethrin 0.05% + susceptible. Life traits parameters were measured in the progeny and compared between colonies. The control was the susceptible laboratory strain "Ngousso". Kdr allele frequency and the profile of expression of different detoxification genes and oxidative stress genes was checked using qPCR analysis. Gene's expression was compared between the first and the last generation of each colony and in field populations collected before and during larviciding.

RESULTS

An increase in mosquito susceptibility to deltamethrin and permethrin was recorded for the field populations after larviciding implementation. Resistance intensity to deltamethrin was found to decrease from high to low in field populations. Only the colony vectomax+deltamethrin+susceptible presented a high susceptibility to deltamethrin after 21 generations. The kdr gene frequency was found to be unchanged in the field population and laboratory colonies. A significant decrease in the overexpression profile of Gste2 was detected in field population after larviciding implementation. Other genes showing a similar pattern though not significant were Cyp6z1, Cyp6p1 and Cyp6g16. Concerning fitness only the colony vectomax+deltamethrin+susceptible was found to display a fitness profile similar to the susceptible colony with high fecundity, high hatching rate, short development time and long adult survival rate.

CONCLUSION

The profile of the field population supported reversal of phenotypic resistance to pyrethroids however no reduction in the frequency of the kdr allele was recorded. Some detoxification genes were detected less overexpressed. The study suggest that reversal may take longer to achieve in a population expressing a very high resistance profile and under continuous insecticide selection pressure.

Provision of family planning services by community health workers in urban slums of Cameroon

Over 50% of pregnancies in slums are unintended, signifying unmet family planning (FP) needs. In Cameroon, about 60% of city dwellers live in slums where basic health services including FP is lacking. With an acute shortage of health personnel in Africa, community health workers (CHWs) can play a vital role in administering basic FP services. The Cameroon Baptist Convention Health Services implemented a pilot project to reduce the unmet FP needs in urban slums through utilization of CHWs. We found that with adequate training and support, CHWs can successfully provide basic FP services in urban slums.

Universal test and treat in Cameroon: a comparative retrospective analysis of mortality and loss to follow-up before and after a strategic change in approach to HIV care

Introduction

an increasing number of persons living with HIV (PLHIV) are accessing antiretroviral therapy (ART) since the adoption of the universal test and treat (UTT) policy by Cameroon in 2016. We sought to evaluate the effectiveness of the UTT approach to keep this growing number of PLHIV on a lifelong treatment.

Methods

a retrospective cohort analysis was conducted at the Nkongsamba Regional Hospital between 2002 and 2020, using routine data to compare the cumulative incidence of loss to follow-up (LTFU) and mortality between PLHIV initiated on ART under UTT guidelines and those initiated under the standard deferred approach. Chi-squared test was used to compare the risk of attrition between the guideline periods while multiple logistic regression modelling was used to adjust for confounders.

Results

of 1627 PLHIV included for analysis, 756 (46.47%) were enrolled during the era of UTT with 545 (33.54%) initiated on ART on the same day of HIV diagnosis. The transition to the UTT era was associated with an overall reduction in the risk of LTFU by 73% (aOR = 0.27, 95%CI: 0.17 - 0.45). There was modest evidence that the odds of mortality had increased under the UTT policy by about 3-fold (aOR = 2.86, 95%CI: 0.91-8.94). Same-day initiation had no overall effect on LTFU or mortality. LTFU was lower among the same-day initiators in the first 24 months but increased thereafter above the rate among late initiators.

Conclusion

overall ART programme implementation under the UTT has led to a significant decline in LTFU though mortality appeared to have increased. Ongoing efforts to keep patients on long-term treatment should be sustained while other innovative schemes are sought.